Collision Avoidance System by Aerialtronics

Sense and avoid is key tool in the integration of Small Unmanned Aerial Systems (sUAS) in the National Airspace System (NAS).  Incorporating sensor technology on sUAS is incredibly challenging as the overall vehicle weight is typically less than 55 lbs.  Therefore, it is difficult to integrate an exteroceptive sensor that is capable of detecting, sensing, processing, reacting, and avoiding potential threats.  The power requirement and associated proprioceptive sensory equipment necessary to properly design a system most often requires larger vehicles with more capability.  Larger UAS have a larger electrical design infrastructure and can incorporate a variety of sensors to develop an overall sense and avoid solution.  Optical sensors, LiDAR, and Air-to-Air Radar Subsystems (AARSS) are all examples of sensory equipment used on large UAS. 

Aerialtronics has developed a new Collision Avoidance System (CAS) that utilizes a virtual sensor that can build a map of potential obstacles.  The Aerialtronics CAS will be capable of ultra-quick real-time scanning of the Altura multirotor surroundings and detecting obstacles within a predefined safe distance (sUAS News, 2014).  The Aerialtronics product is a plug and play solution that is easily installed in minutes.  This added feature decreases the risk of collision when inspecting telecommunication towers, utility poles and oil rigs, particularly in windy conditions.  Aerialtronics’ sense and avoid solution detects both static and moving objects up to 15 metres away and the four sensors mean the Altura Zenith can locate objects up to a 360° field of view (Aerialtronics, 2015). 

The Zenith with CAS installed relies on ultrasonic technology that determines distance from an object based on how long it takes for a released sound to return.  The operator can specify the safe distance by selecting different modes.  CAS will consist of several unique technologies including various types of state of the art obstacle detection sensors, advanced data fusion algorithms as well as tightly integrated collision avoidance algorithms with guidance, navigation and control system (sUAS News, 2014).  The sensor has two ultrasonic sensors mounted at the end of flexible shaft.  The shaft firmly screws into each end of the quadcopter.  A full 360 degree solution will have four shafts protruding from each arm of the quadcopter. 

  

Aerialtronics plans to take their sense and avoid solution one step further than onboard sensors.  By combining the data from the CAS system with the Intelligent Transportation System (ITS), Aerialtronics will build a complete picture of the surroundings the vehicle is operating in.  This integration is an important step to combine ground based sensory with airborne sensory for a refined air picture.  By connecting ITS data to CAS, Altura systems will be capable of foreseeing danger and responding in a timelier manner, ultimately making airspace safer and more accessible (sUAS News, 2014).

sUAS integration into the NAS will require a sense and avoid solution that will bring confidence to the public in regards to safe and responsible operations.  The CAS solution proposed by Aerialtronics combined with ITS will create an air picture that allows the aircraft to operate seamlessly within a fluid environment.      

Aerialtronics (2015, February 2).  Aerialtronics Adds Sense and Avoid Technology to Zenith UAS.  Retrieved from http://www.aerialtronics.com/2016/02/aerialtronics-adds-sense-and-avoid-technology-to-zenith-uas/

sUAS News (2014, September 2).   Aerialtronics Improves Safety by Incorporating Sense and Avoid.  Retrieved from  http://www.suasnews.com/2014/09/aerialtronics-revolutionarily-improves-safety-by-incorporating-sense-and-avoid/

Bluefin-21 Data Display and Presentation

6.4 - Research Assignment: Control Station Analysis
By
Chris Bennett

General Dynamics purchased Bluefin robotics, a manufacturer of Unmanned Underwater Vehicles (UUV) in February of 2016.  Bluefin has a fleet of UUVs that have a multitude of uses for undersea missions for both commercial and military applications.  Most of the UUV vehicles are known as Bluefin-X with differentiation based on the overall size and sensor capability.  The Bluefin-9 is the smallest and lightest vehicle whereas the Bluefin-21 is much larger and has the ability to carry more sensory options and payloads.  

For an operator of an UUV it is important to understand the data depiction and presentation strategy of that vehicle.  The Bluefin suite of vehicles utilize an Operator Tool Suite to control their vehicle and display data.  Bluefin’s Operator Tool Suite is a comprehensive software package that provides the interface between the vehicle and the operator for all mission phases (General Dynamics, n.d.).  The Operator Tool Suite is broken into three distinct areas: Mission Planner, Dashboard, and Lantern.  This Windows-based tool suite includes everything necessary to run and manage the system, including vehicle check-out and testing, mission planning, vehicle communications, mission monitoring and execution, data management, and post-mission analysis (General Dynamics, n.d.).

Mission planning is one of the most vital tools necessary as part of the data depiction and presentation strategy of a UUV.  Getting the vehicle safely to and from the target area is vitally important and without consistent radio signals between the ground station and the vehicle, it is important that the mission plan be mitigated prior to mission execution on a UUV.  Mission planning and verification is done via simple to use “widgets”.  Planning takes place on top of a chart-based view which accepts raster or digital charts (General Dynamics, n.d.).  The operator can input safety criteria in addition to operational constraints, and decision points that will recover the vehicle if it isn’t performing as expected.

The Bluefin Dashboard is an intuitive design for vehicle testing, checkout, and mission monitoring.  Dashboard tools enable the operator to track vehicles against a chart-based interface which includes ship position indicators, mission plans, and a variety of operator-specified annotations (General Dynamics, n.d.).  A variety of sensors display telemetry data from the Bluefin to the Dashboard which enables the operator to monitor the vehicle status.  The fastest return link from the Bluefin is automatically selected through the dashboard to relay data.

Lantern is the interface that allows the operator the ability to conduct post-mission analysis.  Lantern has the ability to operate efficiently with other available software components for mission analyzation.  It combines survey tracklines, vehicle data, contact locations, and user-entered annotations in straightforward chart-based windows (General Dynamics, n.d.).  Lastly, normal zoom, and accurate geo-referenced coordinate data can be gathered by manipulating the Lantern tools.
Bluefin-21 was utilized during the search for Malaysia Airlines Flight 370 and suffered numerous setbacks, most characterized as “communication issues”.  Another fault was found that the vehicle reached its maximum depth of 4,500 meters and was then forced to surface.  Without further details on that particular event, it is difficult to offer recommendations on either situation.  In most cases, UUVs benefit from a tethered cable that will allow operators to oversee the mission in live time.

Because of the dispersing action of water, it is incredibly difficult to maintain reliable communications between a ground station and vehicle.  In open waters, with little chance of obstacles, a tether would allow data to be received instantaneously from the vehicle.  Additionally, live video feed and telemetry data from the sensors can be interpreted by an operator utilizing the Lantern software.  It doesn’t appear that the dashboard is operator intuitive and lacks the typical “caution” (yellow) and “warning” (red) readout display most often found in aircraft design.  By integrating standard markings, the operator can be given warnings as the vehicle approaches specific limits (i.e. yellow-caution at 3,900 meters, red-warning at 4,200 meters).  This change would allow an operator to possibly intervene prior to the vehicle exceeding its operational limit of 4,500 meters and subsequently being forced to surface.

The Bluefin suite of vehicles are a well-designed UUV concept that use simple Windows based software to display and interpret data from the underwater vehicle.  By applying caution and warning design considerations used in most aircraft, the display indications can become more refined and intuitive for an operator to perform the vehicle mission with greater success.

REFERENCES
General Dynamics (n.d.).  Operator Software; Bluefin Robotics.  Retrieved from http://www.bluefinrobotics.com/technology/operator-software/

Insitu ScanEagle

The Insitu ScanEagle, built by Insitu, and now in partnership with Boeing Corporation, is a simplistic Unmanned Aerial System (UAS) with a basic approach to design.  The 10 foot wingspan, 4 foot length, and 44 pound max gross weight places this UAS in the Group 2 (Medium) category.  With a speed of 75 knots and a maximum endurance of 19,500 feet the Scan Eagle is a competent aircraft that has logged over 22,000 operational hours in support of OIF.

 

The exteroceptive sensor chosen for the ScanEagle is a Sensor Turret System housing an advanced Electro-Optical (EO) Camera and Infrared (IR) camera.  The EO camera is capable of streaming color video at a 25:1 optical zoom with image stabilization.  The uncooled IR camera utilizes long-wavelength technology with an 18 degree field of view that captures images at 30 frames per second.  The IR camera is also image stabilized. The video feed (which is in NTSC format) can be displayed on a monitor and/or recorded onto the hard disk onboard the Ground Control System (GCS) (Lim, 2007).  Additional sensors include chemical/biological sensors, magnetometer, and a laser designating system.

ScanEagle has completed additional testing with another crucial exteroceptive sensor to increase its capability.  The fitting of Signature Aperture Radar (SAR) to the Boeing ScanEagle was done in partnership with ImSAR and Insitu and was no mean feat - the NanoSAR is a 2-pound system approximately the size of a shoebox (Hanlon, 2008). Beyond its military role, SAR significantly extends the capabilities of a UAV, enabling it to be more effectively used for such diverse applications as search and rescue in adverse conditions, fire line location and tracking through smoke, iceberg detection, ice pack analysis and the detection of debris or oils spills on the ocean or other bodies of water (Hanlon, 2008).  This initial test with this additional sensor capability greatly increases the usefulness of ScanEagle.   The testing to date has seen the ScanEagle collect data on an onboard 32 GB solid state drive with the imagery later created on the ground (Hanlon, 2008). 

  

The ScanEagle uses a flight computer for its most crucial “brain power”.  This proprioceptive sensor is crucial to maintaining stabilized flight parameters.  The design of the ScanEagle is based on flight path control, not operator flight control (Wilke, 2007). In the Scan Eagle, it uses a Technologic Systems, TS 5700 PC 104 Embedded Single Board Computer with a 133 MHz AMD 586 Processor (Lim, 2007).  Other proprioceptive sensors, such as a Navtech GPS receiver system, deliver vital information to the flight computer in order for the Scan Eagle to fly to various waypoints, orbits, or complete object tracking.  These sensors also allow for automatic and manual control modes for the Sensor Turret System.   The unit, which contains solid-state gyros and accelerometers, magnetometer, GPS receiver and air data pressure transducers, provides attitude and heading measurement to high accuracy (ScanEagle, n.d.).      

Data dissemination is available through various standard formats and can include video with synched metadata, snapshots, or cursor-on-target information (Wilke, 2007).  The partnership between Boeing and Insitu has allowed more capability in systems configuration tracking.  Data exploitation is enhanced by utilizing Sarnoff’s TerraSight system (Wilke, 2007).  ScanEagle has a 900MHz UHF datalink and a 2.4GHz S-band downlink for video transmission (ScanEagle, n.d.).  Data collection is contained within the GCS and can also be removed as needed. 

Hanlon, M. (208, March 18).  ScanEagle UAV gets Synthetic Aperture Radar (SAR); New Atlas.  Retrieved from http://newatlas.com/scaneagle-uav-gets-synthetic-aperture-radar-sar/9007/

Lim, H. (2007, December).  Network Payload Integration for the Scan-Eagle UAV; Naval Post Graduate School.  Retrieved from http://www.dtic.mil/dtic/tr/fulltext/u2/a475874.pdf

ScanEagle (n.d.).  ScanEagle, United States of America; Naval-Technology of America.  Retrieved from http://www.naval-technology.com/projects/scaneagle-uav/

Wilke, C. (2007, March 2).  Scan Eagle Overview; SAE Aerospace Control and Guidance Systems Committee.  Retrieved from http://www.csdy.umn.edu/acgsc/Meeting_99/SubcommitteeE/SEpubrlsSAE.PDF